Metadata Namespace Management of Distributed File System

With the rapid development of internet, the distributed file system is gradually facing problem of supporting concurrent 10K and 100K servers operations, so it now becomes an important issue that how to improve performance of the metadata server in high concurrent reading /writing environments. This paper designs and implements the distributed file system named Raccoon FS, researches and solves the problem of low response speed of namespace management brought by the lock competition in distributed file system, and it proposes a new metadata namespace management method that realized the technology of Copy-On-Write and Multi-Version Concurrency Control in B+ tree. Through the evaluation, the namespace management that combined COW and MVCC in B+ tree greatly improved the read and write performance.